This is a pretty strange line. Complete unknown. What does he hold?

Full Tilt No-Limit Hold'em, $0.25 BB (8 handed) Full-Tilt Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG+1 ($5)
MP1 ($24.75)
Hero ($24.65)
CO ($22.25)
Button ($19.95)
SB ($16.80)
BB ($4.05)
UTG ($31.15)

UTG calls $0.25, 1 fold, Hero raises to $1.25, 4 folds, UTG calls $1.

Flop: ($2.85) 7, 6, 9 (3 players)
UTG checks, Hero bets $2.5, UTG calls $2.50.

Turn: ($7.85) 7 (3 players)
UTG checks, Hero bets $5, UTG calls $5.

River: ($17.85) T (3 players)
UTG bets $14.5, Hero calls $14.50.

Final Pot: $46.85