Prashanth

The actor suffered a setback in the mid 2000s, when he went on signing spree only for several of his projects to become shelved after being launched. In September 2004, Thiagarajan launched Police, a remake of the Hindi film Khakee and the film received coverage from the media after producers had approached Amitabh Bachchan and Aishwarya Rai for key roles. In interviews during the period, Thiagarajan mentioned the grand scale of the project citing that schedules would also be shot abroad; however the film failed to progress.

Prashanth next signed on to appear in Susi Ganesan's village acton story Sakkarai in October 2004 only for the film to be discontinued after a grand launch ceremony. In mid-2005, the actor began filming for A. Venkatesh's Petrol and after several leading actresses were approached to play the lead heroine, newcomer Seema was selected. The film continued to shoot schedules for close to a year across India, but Prashanth's marital problems eventually led to delays in the director's schedule and the film remains uncompleted. In December 2005, Prashanth accepted and started work in R. K. Selvamani's Pulan Visaranai II, a sequel to the director's 1990 blockbuster, with the film's soundtrack and trailer released by 2006.

Moreover, the actor's three films which released in 2006 had all been severely delayed during production and neither of the films made any notable impact at the box office. Jambhavan, which released in September 2006, had gone through production hassles notably after the lead heroine Nila had a spat with the producers and delayed the film's shoot. The film opened to negative reviews and became a failure commercially.

Debutant director's Bhuvanaraja's Adaikalam, a family drama which had been completed the previous year, gained positive reviews but the low key nature of the release hampered any chance of a successful box-office run. Featuring no lead heroine, the film told the tale of an estranged family with Thiagarajan, Saranya and Uma also in the cast and a critic noted that "as a brother and a bitter son, Prashanth has churned out what is arguably one of his better performances till date.

His final release of the year was Shiva Shanmugam's Thagapansamy which featured Prashanth in the role of a village do-gooder, with Pooja and Namitha in other pivotal characters. The film opened to below average collections and average reviews from critics, though Sify.com noted to "watch the film for the one-man-show of Prashanth, as he is the only silver lining in a film with a confused and confounded plot.

Prashanth had no film releases between January 2007 and April 2011, but was involved in the production of two heavily delayed productions during the period - Ponnar Shankar and Mambattiyan. The actor also invested in business opportunities, opening a 12 floor jewellery store in T Nagar, Chennai in 2008.