As Cambridge and Woreester police sought for fresh leads on Friday's $50,000 Coop robbery, the holdup car turned up yesterday morning, abandoned on a side street in Central Square.

The auto had been stolen from the Commander Hotel on Thursday and was apparently deserted by the bandits less than ton hours before before being discovered, police said.

Local police authorities meanwhile squelched rumors headlined in the Boston Herald that the robbery was a "student prank" and that the money would be returned as dramatically as it was taken. One sergeant said, "I wish I could commit a prank like that."

Worcester Main Clue

Forty-mile distant Worcester, where the car's license plates were stolen continued to supply the most promising angles on the smoke-bomb holdup, as a squad of detectives combed the city over the weekend in an effort to apprehend the men responsible.

Clue to the Worcester leads was supplied by reports that a gang, specializing in daylight robberies, had been seen there for the last two weeks. Police also suspect this group to be the same which committed the sensational $108,000 holdup of the Sturtevant machine company in Jamaica Plain two months ago.

Bombe Common

Ballistic exports, still examining the two smoke bombo which the robbers used to distract attention during their crime, said that the implements could very possibly be war surplus material of the type currently being distributed in New England.

The big problem facing police last night was the fact no member of the gang had ever been seen in the Square previous to the holdup.