Investigators for a US Sheriff want actress Lindsay Lohan charged with battery for an alleged scuffle with a drug dependency centre technician.
A two-week investigation shows Lohan violated her probation during the altercation and details will be sent to the Los Angeles County Probation Department this week, Riverside sheriff's Sergeant Joe Borja said.
A Beverly Hills judge has said Lohan will be jailed if she violates probation.
Investigators expect to take their case to the Riverside County district attorney's office this week for possible prosecution, Borja said.
Lohan returned to the Betty Ford Centre at Palm Desert on December 12 after curfew and refused rehab worker Dawn Holland's request to take a breath test.
Lohan is accused of pushing Holland, who then dialled 911, and Lohan ripped the phone away and injured Holland's wrist.
Lohan has been receiving treatment at Betty Ford, about 120 miles east of Los Angeles, since late September.
Los Angeles Superior Court Judge Elden Fox, who has overseen Lohan's probation for her three and a half year-old drunken driving case, required Lohan to remain at the rehab centre until Monday.
John Hall, spokesman for the Riverside County district attorney's office, said his office expected to receive investigators' findings this week.
If Lohan is prosecuted in Riverside County, the Los Angeles County probation department would be notified, he said. The actress is due back in court on February 25 in Beverly Hills for a hearing at which Fox is expected to address Lohan's probation and the Betty Ford altercation.