Builders working on Brighton and Hove Hebrew Congregation's Middle Street site have found a white-tiled mikveh in a cottage sold to the local Hillel committee last year for use as a student drop-in centre. The mikveh was discovered beneath a trapdoor under the cottage floorboards.

"The founders and builders of our community in Middle Street knew at its inception that a mikveh is at the centre of Jewish life," observed BHHC's Rabbi Herschel Rader.

But local historian and Middle Street Synagogue guide Gordon Franks was mystified by the discovery.

"There is no mention of the mikveh in the synagogue architect Thomas Lainson's plans," he said.

"When the synagogue opened in 1875, its first minister was the Rev Abraham Jacobs.

"We do not even know whether the mikveh was intended for his family or intended for the Jewish public as well."

Aileen Hill of the Hillel committee said "the builders have told us that the mikveh is unusable as it isn't linked to the necessary water supplies".