An Australian death row convict married his girlfriend in prison toay, a day before his possible execution by an Indonesian firing squad for drug offences.

Andrew Chan, who was convicted in 2006 along with fellow Australian Myuran Sukumaran for trying to smuggle heroin out of Indonesia, exchanged vows with Indonesian fiancee Febyanti at a maximum security prison in central Java. A small group of family and friends attended the ceremony.

Download: Image(Large) Caption XML All Febyanti Herewila, fiancee of Australian death row prisoner Andrew Chan, walks to a ferry while on her way to visit him on the prison island of Nusakambangan.

"It's tough times but it's happy times at the same time," Michael Chan, Andrew's brother, told reporters outside the Nusakambangan island jail, where the executions will take place.

"We just hope that the president somewhere will find some compassion and mercy for these two, this young couple so they can carry on with their lives."

Chan and Sukumaran are among a group of nine drug convicts, mostly foreigners, that are due to be executed after President Joko Widodo refused their clemency pleas.

Indonesia's Constitutional Court agreed to consider on May 12 a last-ditch legal challenge brought by Chan, his lawyer said, raising hopes their execution could be delayed. But the Attorney General's office later said the executions would take place this week.

The married couple met while Chan was imprisoned in a Bali jail. Febyanti, an Indonesian pastor, regularly visited the jail as part of her work, local media said.

Febyanti and other family members will no longer be able to visit Chan starting from Tuesday afternoon, hours before his expected execution.