Lincolnshire Police are appealing for bikers who witnessed a fatal crash on the A631 Gainsborough Road at Hemswell Cliff to get in touch.
A 48-year-old male motorcyclist from the Doncaster area was killed at the scene of the crash at 8.20pm on Monday, August 7.
The fatal crash involved a Kawasaki motorbike which collided with another motorbike.
In a statement, a Lincolnshire Police spokesperson said: “We are appealing for further information and would like to hear from anyone on a motorcycle who may have stopped at the scene around the time of the collision and who has not already spoken to police.
“They are thought to have ridden from the scene in the direction of Gainsborough.
“Please call us on 101, quoting incident number 509 of August 7.”