Hamas could halt talks on the release of an Israeli soldier seized in a cross-border raid and now being held in the Gaza Strip if Egypt does not free one of its leaders, a Hamas official said.

Soldier Gilad Shalit was abducted by militants from an Israeli army base in June 2006.

In exchange for his release, Hamas has demanded that Israel sets free hundreds of prisoners it holds.

It also wants Egypt to release Ayman Nofal, a senior Hamas military operative arrested in Egypt on suspicion he was planning to attack targets there.

Egypt has been trying to mediate a prisoner swap.

But Hamas leader Youssef Farhat told a rally of hundreds of Nofal's fellow militants that Egypt could not play a mediation role as long as it held him.

"We have put the file of Shalit in the fridge and it will remain frozen unless Ayman Nofal is freed," Farhat said.

Hamas spokesman Sami Abu Zuhri said the comments reflected frustration within Hamas over the situation.

"Nofal's continued detention is annoying and it has topped the agenda of all talks with Egyptian officials. We hope Egypt can end it by freeing him," Abu Zuhri said.

Hamas won a parliamentary election two years ago, prompting Israel to impose an economic blockade on the Gaza Strip.

It blew up the Rafah border crossing in January, allowing hundreds of thousands of Gazans to pour into Egypt to stock up on supplies. Egypt resealed the border and has stepped up patrols to prevent another breach.