The incident happened around 11.45pm on Friday, 4 June, 2021 on Limekilns Road.
The crash involved a black Volkswagen Passat and a silver Ford Focus.
Emergency services attended and three men aged 35, 26 and 17 were taken to the Edinburgh Royal Infirmary.
Two of the men were treated for serious injuries and one for minor injuries.
The road was closed for around four hours to allow a full collision investigation to take place.
A 26-year-old man has been arrested in connection with road traffic offences.
Police are now appealing to the public to work out the full circumstances surrounding the incident.
They are urging anyone who has any information surrounding the incident to get in touch.
Sergeant Paul Ewing of Police Scotland’s Fife Road Policing said: “This was a crash that has left two people with serious injuries.
“We are appealing to the public for assistance to establish the full circumstances surrounding the incident.
“Although this happened late at night, we would ask that if anyone has any information that could help with our investigation that they get in touch with officers.
“I would also ask if there are any motorists with possible dashcam footage of the area around the time of the crash that they get in contact with police.
“Police can be contacted by calling 101 and quoting incident number 4593 of Friday, 4 June, 2021.”