Scott Walker, 43, was found badly injured on the A917 between Elie and St Monans, Fife, around 7.45pm on July 8.
The dad-of-one was taken to Ninewells Hospital in Dundee but tragically died the next day.
After an investigation into his death police have now concluded Mr Walker was killed in a hit and run.
In a family statement, Mr Walker's sister said: "As a family we are struggling to come to terms with what has happened.
"Scott was a much loved son, brother and uncle to my four children. He was also the father of an amazing little girl who he will never get to see grow up.
"We want to appeal to the driver involved to please search your conscience and come forward.
"We know you may have panicked and didn't know what to do, but for all of us including you, please do the right thing and speak to the police."
Officers are now looking for the driver of a silver Vauxhall Astra who hit the tragic cyclist before driving off.
Detective Chief Inspector John Anderson from Fife CID said: "We are now confident that Mr Walker was involved in a collision with a vehicle as he cycled east from Elie towards St Monans on Monday evening, and that the vehicle was a silver Vauxhall Astra five door hatchback similar to that shown in the image we have released.
"Through inquiries, we know that the vehicle will have travelled from Elie before the incident and following the collision has continued along the A917 eastbound towards St.Monans.
"We would ask any owners or users of such a car in the East Neuk area of Fife to contact us so that they can be eliminated from our inquiries.
"Likewise any member of the public who has knowledge of such a vehicle being used in the East Neuk of Fife before this incident should contact the Police."You do not have to suspect it was involved, but allow us the opportunity to eliminate it "We have already spoken to a number of owners of this type of vehicle in the area along with other
motorists that were on that road last Monday night.
"Despite this, there are still motorists that have yet to come forward.
"Regardless of what you may or may not have saw, if you were driving on this road last Monday night we need you to speak to us to help us piece together what happened"
"I firmly believe that the answers lie in the local community of the East Neuk of Fife.
"Does a friend, neighbour, or someone you know drive a silver Vauxhall Astra?
"Would this have been driving in the area between Elie and St Monan's last Monday night?
"It may not appear damaged or indeed you may not have seen it since. Has someone confided in you about what happened?
"If you have any information regarding what happened or a vehicle matching this description, please come forward and contact officers."