According to Hearn, the heavyweight fight needs to be sanctioned, with Joshua’s IBF belt and potentially the WBA and WBO titles on the line.
On Wednesday, Britain’s Tyson Fury relinquished his WBA and WBO beltsand his boxing licence was then suspended.
The British Boxing Board of Control revoked Fury’s licence “pending further investigation into anti-doping and medical issues”, after the 28-year-old admitted he had been taking cocaine to help him deal with depression.
Fury beat Ukraine’s Klitschko last November to win the WBA, IBF and WBO titles but withdrew from two scheduled rematches.
Britain’s undefeated heavyweight champion Joshua, 27, was scheduled to defend his title on 26 November in Manchester.
Hearn says the fight between Joshua and Klitschko will likely be held at the 21,000-capacity Manchester Arena.
STORY BY BBC SPORT