Babcock, 23, has been missing since June 2012. Millard, 27, is charged with first-degree murder in connection with Bosma's death.
"I can say that [Babcock and Millard] were romantically linked, although I would not say they had a traditional dating relationship," said Det. Mike Carbone.
- Tim Bosma slaying suspect Millard's farm searched again
"I can confirm at this time that there appears to be phone contact on July 3, 2012, between Laura Babcock and Mr. Dellen Millard," Carbone said. "I cannot comment any further on these specific records as we’re attempting to speak to other individuals who have been in contact or have been identified as having contact with Laura."
Carbone said Babcock was known to be involved in the sex-trade business as an internet escort for several months prior to her disappearance, but he added that, as far as he knew, Millard was not involved in the sex-trade business.
A farm owned by Millard in Waterloo Region was searched after police received some information, but no new evidence was found in the case, Carbone said.
Police also said that the disappearance of Babcock is still being treated as a missing person case, and not as a homicide.
Bosma, 32, disappeared on the evening of May 6 after he took two strangers on a test-drive of a truck he was trying to sell.
A second man, 25-year-old Mark Smich of Oakville, Ont., was arrested on May 22 and has since been charged with first-degree murder. A third suspect is still being sought by Hamilton police.
- Accused in Tim Bosma disappearance staying silent, lawyer says
Shawn Lerner, a former boyfriend of Babcock's, told CBC News he examined Babcock’s phone bill for clues after she went missing and noticed several calls to Millard.
Lerner said Babcock had known Millard "for several years."
After Bosma went missing, a police forensic team searched a farm Millard owns near Cambridge, Ont.
Police discovered Bosma's remains, which they said were "burned beyond recognition."
After Millard's arrest, police took another look at the Babcock case and the suicide of Millard's father, Wayne, last fall.
Carbone said the investigation into Wayne Millard's death remains ongoing, but added that he could not comment further on that case.