The parliamentary standards watchdog has found "there was no breach of the rules on paid lobbying" by former foreign secretaries Sir Malcolm Rifkind and Jack Straw after an investigation into cash-for-access allegations.

Both denied wrongdoing and referred themselves to the parliamentary standards commissioner following a sting by undercover reporters.

Kathryn Hudson, the Parliamentary Commissioner for Standards, found that neither was in breach of the code of conduct or the rules of the House "other than in Mr Straw's case - by a minor misuse of parliamentary resources".

Sir Malcolm, who stepped aside as chair of the parliamentary Intelligence and Security Committee and stood down at the election following the claims, said the months after the sting had been a "painful period" for him and his family.

He said: "I thank the Standards Commissioner and the Standards Committee for their very full examination of the allegations by Channel 4 Dispatches and the Daily Telegraph, and their conclusion that these allegations had no substance and were unjustified."

He added: "Channel 4 Dispatches and the Daily Telegraph must recognise the judgment of the Standards Commissioner and the Standards Committee that they were responsible for 'distortion' and for misleading the public in making these allegations.

"It has been for me, for my family and for my former parliamentary staff a painful period which we can now put behind us.

"My public life has continued over the last seven months with the support of colleagues. I am looking forward to the years ahead in very good spirits."

Mr Straw said: "I am naturally delighted that the independent Commons' standards commissioner has cleared me of all wrongdoing."

He added: "Throughout my 36 years' parliamentary career I took great care to act with probity and to treat the rules of the House of Commons with the greatest respect.

"I am most grateful to the Committee on Standards for confirming this. They say that I had been 'particularly at pains to keep his business work separate from his Parliamentary resources', and that I had 'made declarations even when such declarations were not technically required'."

Mr Straw said he regretted "ever having fallen into the trap" and had made serious efforts to check on the bogus company before the meeting "but these checks were not enough to expose what was a deliberate and meticulously planned deception".

He added: "At the time of this sting I said that I felt mortified that I had fallen into this trap but that I had not acted improperly in the meetings, nor more widely in respect of my Parliamentary duties and the rules of the House.

"I have been fully vindicated in this. The commissioner's report gives the full context of what happened, which was not available to the public at the time.

"It has been very sad that the final chapter of my long period in the Commons has been overshadowed in this way.

"The whole episode has taken a huge toll on my family, my friends, and on me, but the commissioner's conclusions and the committee's findings will now enable me to get on with my life."

The former MPs were secretly filmed by reporters claiming to represent a Hong Kong-based communications agency called PMR which was seeking to hire senior British politicians to join its advisory board.

Sir Malcolm was said to have claimed that he could arrange ''useful access'' to every British ambassador in the world because of his status, while Mr Straw boasted of operating ''under the radar'' to use his influence to change European Union rules on behalf of a commodity firm which paid him £60,000 a year.

In a report published by the Commons Standards Committee, MPs said Sir Malcolm and Mr Straw had been "scrupulous in observing the requirements relating to registration of interests".

The commissioner was critical of the sting carried out by Channel 4's Dispatches and the Telegraph.

She wrote: "If in their coverage of this story, the reporters for Dispatches and the Daily Telegraph had accurately reported what was said by the two members in their interviews, and measured their words against the rules of the House, it would have been possible to avoid the damage that has been done to the lives of two individuals and those around them, and to the reputation of the House."

The standards committee raised concerns about media coverage of the allegations and claimed the former cabinet ministers had been "presumed guilty" before any investigation had taken place.

Committee chairman Kevin Barron said: "The committee has not hesitated to take action in the past when a media investigation has revealed the rules have been broken.

"The debate about whether or not MPs should have outside interests is a legitimate subject for media scrutiny, but the rules currently permit it provided that these are registered in the register of members' financial interests, and the lobbying rules are not breached.

"Everything Jack Straw and Malcolm Rifkind said about their earnings was already published online in the register of members' interests.

"What was said in the interviews should have been reported accurately and measured against the rules of the House. Jack Straw and Sir Malcolm Rifkind were presumed guilty before any authoritative investigation had taken place."

A Channel 4 spokesman said: "Channel 4 Dispatches stands by its journalism; this was a fair and accurate account of what the two MPs said. This investigation was in the public interest and revealed matters which were of serious public concern."