Watch: Michael Phelps testifies on anti-doping measures ahead of Olympics

Watch as Michael Phelps testifies on Tuesday, 25 June, to a US House of Representatives subcommittee investigating a doping case involving Chinese swimmers ahead of the 2024 Paris Olympics.

The athlete joins fellow swimming great Allison Schmitt to appear before lawmakers on the Republican-controlled House Energy and Commerce Committee's Subcommittee on Oversight and Investigations about anti-doping measures.

Travis Tygart, the chief executive for the US Anti-Doping Agency, will also testify.

Today's hearing takes place two months after the World Anti-Doping Agency (WADA) confirmed reports that almost two dozen Chinese swimmers tested positive for trimetazidine, a banned drug found in heart medication, before the 2020 Tokyo Olympics.

China's anti-doping agency said the swimmers were inadvertently exposed because of contamination and that they should not be held liable for positive results.

In April, WADA said it would send a compliance team to review China's anti-doping program.