A senior Metropolitan police officer has been found to have "recklessly" misled two pathologists over the possible cause of Ian Tomlinson's death at the G20 protests in London.

Detective Inspector Eddie Hall was investigated after it emerged he told two forensic experts Tomlinson had fallen to the ground in front of a police van before the newspaper seller later came into contact with PC Simon Harwood.

Hall's description of the fall, which did not happen, was formally relayed to two pathologists charged with finding a cause of 47-year-old Tomlinson's death .

The Independent Police Complaints Commission ruled that Hall had been reckless, but accepted that he did not deliberately mislead the pathologists.

The IPCC has opened a fresh inquiry into whether City of London police failed to deal appropriately with information from three other Met police witnesses, who came forward less than 48 hours after the death to say they had seen a colleague push the newspaper vendor to the ground.

Tomlinson's family said senior City of London police officers "misled" them about his death and should face misconduct proceedings after the Guardian revealed the Met witnesses on Monday.

Video footage showed Tomlinson being struck with a baton and violently pushed from behind on 1 April 2009 on Royal Exchange Buildings. An inquest jury found last week that Tomlinson was "unlawfully killed" by the police officer, and died from internal bleeding as a result of injuries sustained by the push.

Jurors heard evidence from four pathologists, including Dr Ken Shorrock, one of the pathologists formally instructed by Hall on behalf of the Met at St Pancras mortuary on 22 April 2009.

The police officer told Shorrock that Tomlinson had been seen to fall to the ground on Lombard Street, minutes before the newspaper seller came across Harwood. The same information was supplied to Dr Ben Swift, the pathologist instructed by Harwood, who was also present during the examination.

In his defence, Hall said an IPCC investigator had told him Tomlinson had fallen in front of a van. The IPCC investigator, Chris Mahaffey, denied this.

Tomlinson passed through Lombard Street as he tried to find a route home through the G20 protests and was forcefully escorted out of the road by police officers.

But the IPCC said there was "no evidence of any kind" that suggested he fell to the ground at this point.

Releasing its findings, the IPCC confirmed "misinformation was supplied by the police to the pathologists". Investigators found that while Hall did not "intentionally mislead" the pathologist, his erroneous briefing jeopardised the investigation, inquest and possible prosecution.

The Met was "directed" by the IPCC to take action against Hall and he was given words of advice by the head of his unit.

The IPCC report into Hall's briefing was one of three released by the watchdog. Its main report into Tomlinson's death contained much of the evidence revealed at the inquest. A third report found police did not deliberately mislead the media over the circumstances of his death.

Deborah Glass, the the watchdog's commissioner for London, said the report into media handling, which was mainly the result of interviews conducted in 2009, contained no evidence to suggest a police "cover-up".

However she said the IPCC's report did not take into account the fact that, just two days after Tomlinson died, three police constables from Hammersmith and Fulham station told seniors they had seen him struck with baton and pushed to the ground.

City of London police was told about the three police witnesses on 3 April, and the IPCC is now investigating why the information was not passed onto its officials, the coroner or the family.

"The CoLP investigators appear to have failed to pass this crucial information on to the pathologist, the coroner, the IPCC or the family until later in the investigation," the family said.

"The family had to wait for the video footage to be released four days later on 7th April before they knew that there had been police contact with Ian Tomlinson."

Tomlinson's widow, Julia, said that on 4 April, the day after police became aware that three witnesses from their own ranks had seen Tomlinson assaulted, she received misleading information.

She said that City of London police read her a statement saying Tomlinson had died of a heart attack, there had been no further injuries that would have contributed to his death and there was "no evidence" police in the area were involved. It was not until 7 April, the family said, that video footage was released, showing that there had been police contact with Tomlinson.

"I cried after the statement was read to me. Now I feel that I was misled. It made me believe that the protesters were somehow responsible for Ian's death," she said. "This is wrong and I do feel angry that I was misled like this."