Two coal miners have been freed after spending several hours trapped underground south of Sydney.

The pair were in a cage lift that malfunctioned about 160 metres below ground in Tahmoor near Picton at 3pm.

SIMEC Mining says their "protections systems engaged" while travelling up from the mine pit towards the surface.

The pair were trapped 160m down a 500m mine shaft near Picton south of Sydney. (9NEWS) (9NEWS)

The two miners were trapped for nine hours, finally being freed about midnight last night. (9NEWS) (9NEWS)

The men spent nine hours trapped before finally being brought to the surface and into the arms of their waiting family around midnight.

Luckily they were carrying ration packs, water and oxygen as part of standard safety procedure.

Fire and Rescue NSW says they realised pretty quickly a crane was the only way to get the men out, classifying the operation as "high risk."

They were checked by paramedics but weren't injured after the "high risk" operation. (9NEWS) (9NEWS)

The mine shaft was 500 metres deep, but the lift was stuck closer to the surface than the bottom.

"We utilised a crane and actually set up a secondary lift, we used what's known as a person box and lowered that down - transporting the miners into the new box and moving them out one at a time," Fire and Rescue's Josh Turner told 9NEWS.

The rescue started at 3pm and carried on into the night. (9NEWS) (9NEWS)

SIMEC Miniing is investigating. (9NEWS) (9NEWS)