THE Church of Scientology is denying claims by Nick Xenophon of a cover-up, while the senator remains frustrated in his call for a parliamentary inquiry into the religion.

Yesterday Stephen McBride, whose Scientologist brother committed suicide two years ago, travelled to Canberra to plead with the Prime Minister, Kevin Rudd, to order an investigation of the church.

A coroner's inquiry into his 2007 death found that Edward McBride had taken out a $20,000 loan to pay for his Scientology courses. In the days before he died, the Defence Force officer was contacted by church members 19 times. And against the wishes of police, the church sent files on Mr McBride to the US where they remain out of reach.

''The bombardment of 19 telephone messages backed him into a corner with no room to breathe,'' Mr McBride said.

''We've been through hell the last two years - please don't let my brother's death be in vain.'' But Senator Xenophon and the Greens have so far been unsuccessful in their calls for an inquiry. The Opposition has signalled it would not support an inquiry, and it is understood the Government is cool on the idea.