Peter Sutcliffe has reportedly been questioned in prison in Durham by detectives investigating up to 17 unsolved attacks in Yorkshire.
It has been reported by the Sun that the victims, all of whom survived, sustained injuries similar to those inflicted by Sutcliffe on his 20 known victims.
The Bradford lorry driver was jailed in 1981 for 13 murders and seven attempted murders during a six-year period in which West Yorkshire was convulsed with fear.
West Yorkshire Police declined to comment on the report, which said some of the unsolved cases involved the use of the same kind of hammer carried by Sutcliffe.
Most of the victims have been linked with Sutcliffe repeatedly since his arrest, but the 70-year-old killer, who now uses the name Peter Coonan, has always denied responsibility.
The new round of questioning was said to have been conducted at Frankland Prison in Durham, to which Sutcliffe was moved last summer after a ruling that he no longer needed to be housed in a secure hospital.
The Sun reported that the cases included that of Tracy Browne who, at 14, was hit with a hammer in Silsden, near Keighley, in August 1975, two months before Sutcliffe claimed his first murder victim, 28 year-old Wilma McCann, in Leeds.
Police are also said to be investigating the cases of Gloria Wood, 28, in Bradford, a year earlier, and Yvonne Mysliwiec, who was a local newspaper reporter in Ilkley when she was attacked in a similar manner.
Other unsolved attacks from the period include those of shop assistant Rosemary Stead, 18, Bradford resident Maureen Hogan, both in 1976, and student Ann Rooney, 22, on the outskirts of Leeds, in 1979.