WARNING: Graphic content

Diners have described the moment they saw a man accused of carrying out a horrific double murder arrive at a nearby McDonald’s for a late-night dinner.

The bodies of 39-year-old pregnant woman Athena Georgopoulos and 50-year-old Andrew Gunn were found inside a home on Adrienne Crescent in Melbourne’s Mount Waverley about 9.55pm on Monday.

Know the news with the 7NEWS app: Download today

WATCH THE VIDEO ABOVE: Suspect’s fast-food feast moments after a sadistic double killing.

7NEWS understands Gunn was decapitated, with his head found on a stick.

A 34-year-old homeless man, Ross Judd, was arrested at Westall train station, in Melbourne’s south east, about 1.40am on Tuesday.

Some diners reported allegedly seeing a man matching his description at the McDonald’s on Dandenong Rd in Clayton shortly after 11pm the same night — about a 40-minute walk from where the alleged double murder took place.

One diner, who asked to be identified only as “L”, told www.20304050.best she saw the man arrive with his two pet German shepherds.

L was waiting for her food when she saw the barefoot man wearing a black cotton jacket walk into the packed fast-food outlet about 11.10pm.

L said the man used napkins from the McDonald’s pick-up counter to clean himself up.

“After wiping, he dropped the tissues on the floor,” L said.

L later saw two well-behaved dogs left at the front door.

Feeling uneasy, she took a photo of the dogs before choosing to leave through a side door.

L said the man stood at the pick-up counter for “quite a while” before leaving.

A McDonald’s worker confirmed to 7NEWS that he ordered two medium cheeseburgers with no pickles and a no-sugar Coke.

As L and her partner were about to drive away, they saw the man leaving the restaurant about 11.25pm.

L’s photo of the dogs sparked a flood of comments on social media, with many recognising them by the distinctive scarves they wore.

Many shared photos they had taken when encountering the man and his dogs, with some saying they had even spoken to him.

Most alleged sightings were reported in Clayton, on trains and along the main street.

“He is homeless and lives right downstairs from my apartment. I’ve known him for five months,” one commenter said.

“I used to chat with him often. Those two dogs are named Okey and Gaiya — both are very well-behaved and obedient.”

Neighbour’s account

A neighbour of the slain couple has gone public on social media to share her experience.

She said she heard loud arguing and shouting from next door about 8.50pm on Monday, along with continuous barking from dogs.

The woman explained her neighbours often quarrelled, so she didn’t think much of it initially.

However, her housemate rushed outside to see if he could help.

When he stepped out, he saw a man running towards Ferntree Gully Rd and tried knocking on the neighbours’ door to check on them.

That’s when he discovered the bodies and the graffiti, and immediately called the police.

“At first, he thought it was a stop sign, but when he shone his flashlight on it, he realised it was a human head,” the neighbour said, describing her housemate’s reaction upon seeing the head on a stick.

“When I heard my housemate’s description upon his return, my legs turned to jelly. It was hard to believe that such a terrifying thing had happened just six metres from me,” she said, attaching a photo of her room right next to an SES tent set up for the crime scene.

Both housemates were interviewed by police until about 2.30am on Tuesday.

Detective Inspector Dean Thomas said police were probing the alleged motive.

“We believe that there is a link between our suspect and the address but we’re just working together at this point to make sense of what that means and what it all looks like,” he said.

It is unclear how the man and woman were allegedly killed but it is believed a weapon was used.

Georgopoulos was five months pregnant and had been with Gunn for about three years.

Judd appeared at Melbourne Magistrates’ Court on Wednesday after being charged with two counts of murder.

He is due to return to court on January 13.