City stock broker, 44, gunned down by balaclava'd hitman as he went to catch his train to work Robin Clark, 44 was shot in the thigh at Shenfield station, Essex, at 5.45am Mystery attacker, wearing a black mask sped off in vehicle Police sources said it could be 'some kind of revenge attack' By John Stevens and Anna Edwards and Kieran Corcoran A city trader was shot by an attacker wearing a black balaclava as he went to catch an early morning train to work. Robin Clark, 44, was getting out of his vehicle in a railway station car park with a male friend at around 5.45am yesterday when he was approached by the mystery gunman who shot him once in the thigh before fleeing. Mr Clark, who works at brokers firm RP Martin, was attacked at Shenfield railway station in Essex before being rushed to nearby Basildon Hospital with serious leg injuries. Robin Clark was rushed to nearby Basildon Hospital suffering serious leg injuries which are not thought to be life-threatening No arrests have been made at this stage and the reason for the shooting remains unclear Police sources described the shooting as 'some kind of revenge attack'. Twice-divorced Mr Clark, who is a father of four, last year moved out of the £2.2million five-bedroom house he rented in nearby Ingatestone, Essex, after running into debt. A police source confirmed officers were investigating the possibility the man was shot down by a love rival or because of problems with money. The source said: "It's clear that he meant the shot to be a punishment rather than to kill. It's some kind of revenge attack. Detective Chief Inspector Iain Miller, from British Transport Police, said: "We are able to confirm that a 44-year-old man from Essex arrived at Shenfield railway station this morning in a car shortly before 6am. A police officer removes evidence from the scene of the shooting at Shenfield railway station Detective Superintendent Gary Richardson, who is leading the investigation, added: "At this stage we believe the victim of this assault was deliberately targeted. A taxi driver, who heard the shot being fired, said: "I heard a really loud bang but I just assumed it was a car backfiring. You don't expect people to be running around with guns in a place like this. It's a nice area with lots of expensive houses. Affluent Shenfield is just a short 24-minute train journey from central London and it is a popular town for city workers. Mr Clark works as a euro derivatives trader at RP Martin, a brokerage firm in the City of London. According to a LinkedIn profile in his name, Mr Clark joined RP Martin in June 2013 after a seven-year stint at U.S. firm BGC Partners. A spokesman for the firm yesterday said: "We are aware of this morning's incident and are giving Robin all the support we can." Dozens of armed officers from Essex Police were scrambled to the scene and a large section of the car park remains taped off as investigations continue Detective Superintendent Gary Richardson, leading the investigation, said police believe the victim was deliberately targeted Mr Clark, who has four children aged eight, 11, 14 and 18, had previously studied at the prestigious Duke University in North Carolina. In April, a county court judgment was filed against Mr Clark for debts of £14,653. His first wife Natalie, 42, who lives in Epping, Essex, last night said: "We have been divorced for 10 years and have two sons. This has left me very shaken. Second wife Rhea, 33, who lives in Leigh-on-Sea, Essex, declined to comment. Mr Clark was last night still receiving treatment in hospital. Rail services in and out of London resumed at the station after being suspended for a short while earlier this morning.