Tracy Morgan has been released from a rehabilitation facility as the US comedy star recovers from a serious car accident.

The former Saturday Night Live and 30 Rock star will continue his recovery at home with an "aggressive outpatient programme", according to spokesman Lewis Kay.

Morgan suffered a broken leg and ribs when the limousine van he was riding in was hit from behind on June 7 by a Wal-Mart truck on the New Jersey Turnpike.

The wreck killed 62-year-old comedian James McNair, who went by the name Jimmy Mack. Another comedian, Ardley Fuqua, and Jeffrey Millea were also injured.

Lawyers for Morgan have filed a lawsuit against Wal-Mart in US District Court in New Jersey, claiming the retailer was negligent.

The complaint claims the retail giant should have known the driver had been awake for more than 24 hours, and that his commute of 700 miles from his home in Georgia to work in Delaware was "unreasonable".

It also alleges the driver, 35-year-old Kevin Roper, fell asleep at the wheel.

"As a result of Wal-Mart's gross, reckless, wilful, wanton, and intentional conduct, it should be appropriately punished with the imposition of punitive damages," according to the complaint.

Morgan's lawsuit seeks a jury trial and punitive and compensatory damages.

In a statement, Wal-Mart reiterated that it was "co-operating fully" in the investigation.

"We know it will take some time to resolve all of the remaining issues as a result of the accident, but we're committed to doing the right thing for all involved," Wal-Mart said.

Roper, of Jonesboro, Georgia, has pleaded not guilty to death by auto and assault by auto charges. A criminal complaint also accuses him of not sleeping for more than 24 hours before the crash, a violation of New Jersey law.

A report by federal transportation safety investigators said Roper was driving at 65mph in the 60 seconds before he slammed into the limo van. The speed limit on that stretch of road is 55mph and was lowered to 45mph that night because of roadworks.

Roper had been on the job for more than 13 hours at the time of the crash, the report concluded. Federal rules permit truck drivers to work up to 14 hours a day, with a maximum of 11 hours behind the wheel.

Morgan, a New York City native, was returning from a stand-up comedy performance at Dover Downs Hotel & Casino in Delaware when the crash occurred.