The suspected Gilgo Beach serial killer Rex Heuermann will be charged with a fifth murder, multiple news reports say, after police conducted new searches on New York’s Long Island over the past few weeks.

The expected new indictment may connect the disappearance of two additional women to Heuermann as part of an investigation into the remains of 10 people who were found on or near Gilgo Beach on Long Island 14 years ago.

Heuermann, a New York architect, has already been charged in the killings of four women whose remains were recovered in the area.

Last week, investigators conducted a new, six-day search of Heuermann’s home days after previously searching woodland over nine days in Manorville where the partial remains of two women were discovered in the early 2000s.

A decade later partial remains of those two victims – Valerie Mack, 24, and Jessica Taylor, 20 – were also found on Gilgo Beach, near where the remains of four other women whose murders have already been attributed in a criminal indictment to Heuermann were found.

The Suffolk county district attorney’s office has not said if the woodland search was connected to a search warrant issued for Heuermann’s home.

“As [the DA] has previously stated, the work of the Gilgo Beach homicide task force is continuing,” spokesperson Tania Lopez said.

Lopez on Monday confirmed that a hearing is set for Thursday but did not disclose if a possible indictment would include a new murder charge.

Heuermann, 60, was arrested in July last year near his midtown Manhattan office and charged with the murders of Megan Waterman, Melissa Barthelemy and Amber Lynn Costello. He was later charged with the murder of a fourth woman, Maureen Brainard-Barnes, completing the so-called Gilgo four.

John Ray, an attorney for the family of Shannon Gilbert, whose remains were found near Gilgo beach, has said that Taylor and Mack were tied up in a manner a hunter might use. Heuermann was a hunter, and police recovered about 200 guns from his home in the suburb of Massapequa park.

Heuermann has already pleaded not guilty to murdering four women whose remains were found along Gilgo beach in late 2010 and early 2011 while police were investigating Gilbert’s disappearance.

All of the women who went missing are believed to have been sex workers. But unlike the Gilgo four, Taylor and Mack were dismembered and their remains were found in Manorville years earlier, prolonging the period in which Heuermann was allegedly operating.

Prosecutors allege that Heuermann acted alone in the first four killings – the Gilgo four – and the cause of each woman’s death was “homicidal violence”. They say the evidence includes DNA evidence and burner phones Heuermann allegedly used to arrange to meet the women.

The investigation into the other six sets of remains discovered near Gilgo Beach has remained active. “The thing that allows prosecutors to speak is indictments,” Tierney said in April.