According to Steve Tew, outgoing chief executive of NZR, the 78-year-old former All Blacks captain will start treatment soon.
"Medical professionals have confirmed that Sir Brian has bowel cancer. He is in relatively good health at the moment, and he will undergo treatment soon," Tew told stuff.
In April 2017, Lochore revealed he had beaten two different types of cancer in a year - after being diagnosed with melanoma and prostate cancer during a horrible 2016.
Lochore (78) was born in Masterton and made his test debut for the All Blacks on 4 January 1964 against England in London.
A big man, Lochore was credited for bringing a new dynamic to the role of No 8 - with his corner-flagging, aerial work and unstinting physical onslaught.
Lochore's leadership qualities enthused legendary coach Fred Allen so much he anointed him as All Black captain ahead of a number of more senior teammates.
His deeds from his test debut in '64 to his '71 farewell were top-class, which was saying an awful lot about a pack which had legends like the Meads brothers, Ken Gray, Kel Tremain, Waka Nathan and co.
Lochore brought a statesmanlike edge to his efforts away from the field. He had time for people and the gift of being able to always move on without giving any hint of bad manners or tedium.
His last test was on July 31, 1971 against the visiting British and Irish Lions in Wellington.