The heavyweight fights between Dillian Whyte and Alexander Povetkin and Oleksandr Usyk and Dereck Chisora have been called off due to the coronavirus pandemic.
Whyte was due to step into the ring with Povetkin for an interim WBC heavyweight world title showdown at the Manchester Arena on May 2, but the fight will not go ahead.
The British Boxing Board of Control (BBBofC) on Monday further extended its suspension of boxing events until the end of May, with the United Kingdom in lockdown.
Matchroom Boxing stated that the bout has been rescheduled for July 4, although that is subject to how long the ongoing crisis lasts for.
Usyk was set to do battle with Chisora at The O2 in London on May 23, but that has also been called off and no new date has been agreed.
A BBBofC statement said: "The British Boxing Board of Control has further extended its suspension of boxing tournaments under its jurisdiction for the month of May.
"We will continue to follow the government and medical authorities' advice and keep the situation under review, and when possible explore all options available to find a way of lifting the suspension when conditions permit."
Katie Taylor's world title showdown with Amanda Serrano was due to be on the undercard for Whyte's battle with Povetkin.