The cargo hold of the Swissair jet that crashed off the coast here Sept. 2 held currency, diamonds and jewelry, along with a painting by Pablo Picasso that is believed to have been destroyed when the jet slammed into the water, Swissair officials said today.

''Usually those kind of paintings are sent in some kind of wooden construction that is really not a shockproof container,'' said Urs Peter Naef, a spokesman for Swissair's cargo handling unit in Zurich. ''We don't know for sure but we assume that because of the heavy impact it was probably destroyed.''

Swissair declined to identify the owner of the painting, or say to whom it was being shipped. The painting was identified as ''Le Peintre'' (The Painter), and was shipped as general cargo, not valuable cargo, which would have entailed extra care, the airline said. Swissair officials said the shipping company, which it refused to identify, estimated the painting to be worth $1.5 million.

Because that figure is based on the shipper's estimate, and not the owner's, it could vary widely from the painting's true value.