The Swiss embassy said on Monday it plans to observe the court case of a citizen facing prison and caning for allegedly spray-painting graffiti on a Singapore metro train.

Business consultant Oliver Fricker, 32, will appear for a second time in court on June 21 on charges of trespassing in a metro depot and vandalising a train, for which he could be jailed, fined and whipped with a wooden cane.

Peter Zimmerli, counsellor and deputy head of mission, told AFP the embassy would inform Fricker's family of the case, help him find a lawyer and visit him.

"Also, it is possible that this embassy attends court hearings as an observer," the diplomat said.

"We do not, however, pay bails for our fellow citizens or interfere actively in a running law case."

A judge has impounded Fricker's passport and set bail at 100,000 Singapore dollars (71,000 US), rejecting bis plea for a lower amount because prosecutors consider him a flight risk.

Zimmerli declined to confirm whether Fricker's family would be flying to Singapore.

The court was told during the first session on Saturday that Fricker was with a Briton identified as Lloyd Dane Alexander when he broke into the depot, a restricted zone surrounded by fences topped with barbed wire.

Sources familiar with the case told AFP that Alexander was in Singapore on a tourist visa and left before a police report was filed on May 19.

The Straits Times newspaper reported Monday that Fricker and Alexander spray-painted the words "McKoy Banos" on one side of a train -- believed to be the signature of two shadowy graffiti artists who have left similar marks on trains around the world.

The train has been scrubbed clean but the clip taken by a commuter can still be viewed at http://www.youtube.com/watch?v=1CV4JYKBEQo