The family of a British aid worker killed by an Israeli drone strike in Gaza have urged the Government to hold an independent inquiry into his death.

James Kirby, 47, from Bristol, was one of seven World Central Kitchen (WCK) workers fatally injured in the attack, including two other Britons.

The group was travelling in a WCK convoy leaving one of its warehouses when Israeli armed drones fired munitions at their marked vehicles on April 1 this year.

A memorial service for Mr Kirby, who previously served with the Rifles, will take place in his home city of Bristol on Wednesday.

Speaking ahead of the service, his cousin Louise Kirby described how the family had been “touched” to receive personal letters of condolence from the King and Queen, and former foreign secretary Lord Cameron.

She said: “The murder of James and his fellow aid workers, for whom clearance had been given for their humanitarian work, is a diabolical tragedy.

“Whilst we have had much support, we are still struggling to find answers and accountability for what happened.

“The state of Israel says the murder was an accident. So we were surprised not to have had any contact or condolence from Israel’s ambassador to the UK in London, nor from any Israeli official.

“Any family of a loved one who has been killed needs closure. We need to understand how this disaster could have happened.

“But this is not just about us.

“This is about how Britain looks after its own citizens and their families, when a British citizen has been unlawfully killed by another state.

“There must be a proper, independent inquiry into this attack on innocent aid workers, and for the evidence to be assessed, if appropriate, in a relevant court of law.”

Britons John Chapman, 57, and James “Jim” Henderson, 33, were also killed in the attack.

The relief team’s leader, Australian national Lalzawmi “Zomi” Frankcom, 43, also died, with dual American-Canadian citizen Jacob Flickinger, 33; Polish national Damian Sobol, 35; and their driver, Palestinian Saifeddin Issam Ayad Abutaha, 25.

The Israel Defence Forces (IDF) dismissed two officers and reprimanded three others, calling it a “serious mistake”.

Ms Kirby said the families of those who died had not received contact from the UK Government since the deaths.

They also have not had any information on whether a “credible, independent investigation is taking place”, or the results of any investigation if it has already taken place, she added.

She said: “We appreciate the compassion and respect we have been shown, but we must also have transparency and accountability. How did this happen? Who is responsible? What accountability did they face?

“Just saying ‘sorry it was an accident’ is not enough. We need to know, and we need to know there has been accountability at all levels, so it never happens again.”

Ms Kirby added: “I very much hope the Prime Minister will take our concerns seriously and instigate an appropriate, independent or legal inquiry, not only so we can have transparency and accountability, but so that other British citizens and their families know that their government will act for them, if a foreign state unlawfully kills their loved ones.”

In a statement, a spokesperson for the Government called for an immediate ceasefire in Gaza.

They said: “The death of James and his fellow aid workers was horrific and our thoughts remain with their families.

“Attacks on aid workers are never justified and we remain fully committed to their protection as they support some of the most vulnerable people in the world.

“There must be an immediate ceasefire to protect civilians and aid workers, secure the release of all hostages and ensure much more aid gets into Gaza.

“Israel must guarantee the protection of aid workers, and ensure a tragedy like this cannot happen again.”

A spokesperson for the Israeli embassy said: “This incident was a tragic mistake and we express our deepest sorrow to James Kirby’s family, the other bereaved families, including those of John Chapman and James Henderson, and the entire World Central Kitchen team, who were doing such vital work in extremely challenging circumstances.

“As outlined by the IDF’s Fact-Finding and Assessment Mechanism (FFAM) in the in-depth independent investigation, conducted following the incident, a serious failure was made due to a mistaken identification as well as errors in decision-making.

“In light of this, a brigade fire support commander and brigade chief of staff were dismissed.

“Once again, we express our deepest condolences and sorrow to the families of the bereaved and the WCK team.”