A Lincolnshire police officer claimed that he had been assaulted while on duty after inflicting the injuries himself, a misconduct hearing was told.
PC Anthony Colson is alleged to have made several false statements after claiming that he was assaulted in a car park and had seen a figure running off in to the woods.
A misconduct hearing was told PC Colson alerted the emergency button on his air wave radio after attending the Beechwood car park in Boston just before 8.30pm on 18 November, 2016.
This sparked an “urgent” response with national air support and dog handlers from two outside forces being deployed to the scene to try and cordon off the woods, the hearing was told.
Officers who attended the car park found PC Colson with lacerations to his head and right hand. A craft knife was also found in a ditch just a metre from PC Colson.
Oliver Thorne, opening the case at Lincolnshire Police headquarters, said: “Those officers administered first aid, PC Colson was seen to have lacerations to the head and his hand.
“PC Colson reported he had been assaulted and had seen a figure running off in to the woods.”
The officer was taken to hospital where the cut to his head was treated with glue and his hand was dressed.
But Mr Thorne told the hearing a doctor who was asked to give an opinion on the injuries said that they were “infact self inflicted” by a sharp object.
Mr Thorne added that the doctor would have expected the injuries to be much deeper and varied in shape if they were inflicted by an assailant.
PC Colson, who had served nearly 14 years with Lincolnshire Police at the time of the incident, is accused of breaching professional standards by making several statements he knew or believed to be false. He denies five allegations.
The allegations centre on communications between November 18 and December 16, 2016, in which PC Colson pressed the emergency button on his air wave radio and then repeated that he had been assaulted.
The hearing was told PC Colson gave a first account to a detective the day after the incident in which he stated that he got out of his police car after seeing a torch shining in the woods.
PC Colson stated he felt “something sharp” at the top of his head, and a second blow, and then saw someone running towards the woods.
The officer said: “I looked around and saw lots of blood, and thought what had gone on.”
It is alleged that in a later meeting with two senior police officers PC Colson told them that the incident did not happen. The circumstances of this meeting are disputed by PC Colson.
In concluding his opening Mr Thorne said: “The injuries were self inflicted and were not the result of an assault by a third party.
“When the officer gave those accounts he knew that.”
The hearing which is expected to conclude next week continues.