Worcestershire County Cricket Club has asked police to investigate after it cancelled the contract of batsman Adrian Shankar.
The former Lancashire second teamer left Worcestershire on Thursday.
Worcestershire said it had asked police to investigate the paperwork submitted by the player, which it described as "unacceptable".
The club said it would not comment further while the case was investigated.
The 29-year-old signed for Worcestershire on 10 May but suffered a knee injury on his County Championship debut against Durham.
There are doubts over Shankar's age - he was described as being 26 years of age when he joined Worcestershire. But his birth date was given as May 7, 1982 during his time in the Lancashire second team.
Worcestershire have now passed documentation relating to Shankar's signing to West Mercia Police.
A statement read: "Adrian Shankar was signed by Worcestershire on 10 May after agreeing terms.
"It quickly became evident that documents provided in order to satisfy the club's obligations to the England and Wales Cricket Board were unacceptable.
"This documentation has now been passed to West Mercia Police for investigation and no further comment will be made by the club while the investigation is taking place."