Three men who were killed by train close to London station may have been graffiti artists
Spray cans have been found near where three men died after being hit by what is believed to be a freight train.
The incident happened on tracks near Loughborough Junction station, south London, which is an area popular with graffiti artists.
British Transport Police (BTP) were called to the scene at 7.30am on Monday and rail industry sources told the Press Association the spray cans were found nearby.
The three people may have been killed overnight, when freight trains operate, and sources said the driver did not know his train had hit anything.
Officers were seen taking photographs of graffiti as part of their inquiries.
BTP said they believe the men to have been aged 19, 23 and 23.
The force said they were all from the London area.
The three men have not yet been formally identified, but their families have been informed, police said.
Yesterday evening BTP said efforts were still under way "to establish the circumstances of how the men came to be on the tracks this morning".
Superintendent Matthew Allingham told reporters at the scene that their injuries were "consistent with being hit by a train".
He said: "We were called at 7.34am this morning to Loughborough Junction to reports that three bodies had been found on the track.
"Police officers attended and sadly three men were declared dead at the scene.
"It is believed they died earlier in the morning and injuries are consistent with being hit by a train.
"Officers have delivered the sad news to one family as we believe one of the men was their son.
"However, we are still working to identify and locate the next of kin for the other two men.
"All three men are believed to be in their 20s.
"Our investigation is focusing on how and why the men came to be on the tracks in the early hours of this morning.
"It is far too early for us to comment on the reasons for them being there."
The first call to police was made by a train driver but the force is still trying to identify the train that hit the men.
"We know they were dead for a while before we turned up," Mr Allingham said.
"It is a possibility that it was during the hours of darkness.
"That's why it wasn't reported earlier."
The bodies were found on an elevated section of track with an electric third rail between Brixton and Denmark Hill.
Mr Allingham added: "There isn't a sort of safe refuge up there so if somebody was on those tracks there wouldn't be anywhere for them to go to avoid the train.
"As far as I understand it, if they've been caught in that section of track when a train came through, then they really wouldn't have had much option."
There was unconfirmed speculation that the three may have heard the train coming and lay down, but on the wrong line.
BTP are treating the deaths as unexplained as officers work to understand "how these three people came to lose their life on the railway".
Anyone who was near Loughborough Junction on Monday morning and saw something which may be relevant is urged to contact BTP.
Rail regulator the Office of Rail and Road has opened a preliminary investigation.