In 2009, the Daily Telegraph exposed the scandal. It was, to a large extent, the fault of the Blair admistration. Rather than risk an adverse public reaction to pay rises for MPs, they had given the nod to excessive expense claims and MPs took it to extremes. Here are links to the Telegraph and to Wikipedia.
The intention is to add details of excessive claims to MPs' records on the site. The Telegraph has a long list of data at the link above. I'll stash it here unformatted for now in case it disappears. There is an indexed list here.
There was a fuss in March 2017 about members of the House of Lords trousering £300 a day just for signing in at their state-funded old folks' home. When a three part TV series exposed the conditions in which they are forced to live.
In late March 2017, the Telegraph wrote of an inadvertant data release by the expenses watchdog, IPSA, detailing all payments to "staff, including their wives and family members". Details here.