The widow of one of the 7 July 2005 suicide bombers has lost her high court appeal for legal aid to be represented at the inquest into the deaths of 52 people during the attacks.

Hasina Patel, who was married to the mastermind of the al-Qaida-inspired plot, Mohammad Sidique Khan, was refused funding by Lord Justice Thomas and Mr Justice Silber. They said a decision by the lord chancellor to withhold financial assistance could not be described as unreasonable or irrational, as lawyers on her behalf had claimed.

Thomas said the court had been told Patel's position "was that she was interested to understand why her late husband and the other bombers acted as they did". She was seeking "an opportunity to ask questions of witnesses at the inquest which bore on their knowledge and experience of her husband and others," they said.

He added: "Far from providing any information that might assist the wider public interest, she has flatly and unequivocally declined the opportunity to do so.

"Although requested by this court to show how she could help establish why her late husband and the others whom she knew acted to murder fellow citizens, she has provided not an iota of evidence to us which could show how she could bring a wider benefit, let alone a significant benefit, to the inquests or to the understanding of the victims of the bombing."

Dismissing her case, he said there was no reason why the interests of the claimant could not be dealt with by her giving a statement of her late husband's background and that of the others to the coroner's legal team.

"As a resident of the United Kingdom it must have been her duty to have supplied all that information by now," he said.

"She has refused to provide the information on which the lord chancellor could begin to discern any basis on which separate questioning by her legal representatives could assist in establishing why her late husband and his associates set about murdering fellow citizens."

It was obviously a matter of "significant wider public interest" to understand why her husband, who was born in Dewsbury, West Yorkshire, should have decided to participate in the murder of a large number of innocent people.

The government has granted legal aid to the families of the victims of the 7/7 attacks.

The four bombers – Khan, 30, Hasib Hussain, 18, Shehzad Tanweer, 22, and Jermaine Lindsay, 19 – carried out separate suicide attacks at Aldgate, Edgware Road, between King's Cross and Russell Square and on board the No 30 bus at Tavistock Square.

The families of the victims expressed "relief" at the appeal court decision. Clifford Tibber, of Anthony Gold solicitors, said: "The thought of Ms Patel receiving public funding and the threat of her applying to take part in the inquests has added a new level of unnecessary stress."