Police patrols descended on Preston after a “dangerous and predatory” fugitive was spotted in a residential area.
Officers received a call reporting a sighting of Ivan Leach, 47, also known as Lee Cyrus, in Ingol at around 10.30pm on Monday.
Leach went missing from North Sea Camp, Boston, Lincolnshire on October 9 after day release.
A nationwide manhunt has been ongoing since and police have warned he should not be approached under any circumstances as he poses “a significant risk”.
A Lancashire Police spokesman said the sighting had not been confirmed and that Leach could be anywhere in the country.
She said: “It was reported that Ivan Leach was seen near the Spar shop in Village Green Lane in the Tag Lane area of Ingol.
“Police patrols went out looking for him and the force helicopter was also in the air on Tuesday in relation to that sighting.
“We would urge people if they think they may have seen him to please get in touch.
“All calls will be acted upon.”
Crimestoppers have offered up to £3,000 in reward for information leading to the arrest and conviction of Leach.
He is thought to have committed a serious sexual attack in Tayside, Scotland, since he absconded.
Leach was given a life sentence with a minimum tariff of five years in 2005 for robbing a 90-year-old woman at her Ribbleton home.
His previous convictions include having sex with a 13-year-old schoolgirl and slashing a woman’s throat.
People with information can call police on 101 or contact the independent charity Crimestoppers anonymously on 0800 555 111 or visit Crimestoppers-uk.org.