It is understood Mr Smith has invested an additional £115 million into the fund, which lifts his overall stake in Fundsmith's funds to approximately £200 million.
When the fund launched in 2010 Mr Smith stressed the importance of having 'skin in the game', in order to align his interests with those of investors. At the time he put in an initial stake of £25 million.
Nearly six years on from launch, the fund has proved extremely popular with both DIY investors and financial advisers. It holds £8.2 billion in assets under management.
Effective investment philosophy
Investors have bought into Mr Smith's simple but effective investment philosophy, which is to buy shares in good companies, try not to overpay and then do nothing.
He favours businesses with advantages that are difficult to replicate and looks for high-quality businesses that can sustain a high return on operating capital.
Over five years the fund has returned 168%, outstripping the average global fund return of 67%.
Mr Smith also took aim at rival fund managers who do not invest in their own fund.
“I find it astonishing that many fund managers do not have ‘skin in the game’ in terms of a significant investment in the funds they run," he says. "I wouldn't trust a fund manager who doesn't, and I believe disclosure of this should be mandatory as it is in the US.”
A recent report by Morningstar found half of 15,000 US mutual funds are run by managers who do not invest in their own products.
This story was originally written for our sister magazine, Money Observer.