FILE PHOTO: Presidential candidate Jair Bolsonaro listens to the national anthem during a meeting with women in Porto Alegre, Brazil August 30, 2018. REUTERS/Diego Vara/File Photo

SAO PAULO (Reuters) - Brazilian far-right presidential candidate Jair Bolsonaro, the front runner in next month’s election, will not leave hospital on Friday as expected due to an infection, the Estado de S.Paulo newspaper reported on Thursday.

Citing sources close to Bolsonaro, the paper said he caught a bacterial infection after a catheter was removed during his recovery from a near-fatal stabbing in the abdomen three weeks ago.

Bolsonaro has held the lead for the Oct. 7 election despite being unable to campaign. But polls show leftist Workers Party candidate Fernando Haddad has surged to just six points behind Bolsonaro and would win an expected second-round run-off.

Bolsonaro’s campaign did not return calls.

Spokespeople for Sao Paulo’s Albert Einstein hospital did not immediately reply to requests for comment. The hospital’s daily bulletin on Bolsonaro’s condition issued in the afternoon said he was recovering well and had no fever or pain.

Bolsonaro, 63, was stabbed by an assailant on Sept. 6 as he was carried aloft by supporters in a street rally.