Invesco Perpetual confirmed Monday that Turnbull had been appointed to its emerging market equities team and would be joining the firm in September.
Back in May, it was reported that he would be exiting Neptune to pursue a role on an undisclosed emerging markets team.
Turnbull has spent the entirety of his 10-year investment career at Neptune, joining the firm shortly after graduating from Oxford University.
While there, he became manager of the firm's £32m Neptune China fund in 2009, five years after its launch.
In 2013, he was made Neptune’s head of Chinese equities, a role he balanced with managing the Neptune China fund and working as an assistant fund manager on the Neptune Global Equity fund.
He also previously managed the group’s Greater China Income and China Special Situations funds before they were closed as part of Neptune’s sweeping efforts to restructure its product line.
Neptune’s head of emerging markets, Ewan Thompson, took over the running of Turnbull’s funds as soon as news of his departure broke.
On Turnbull's appointment, Invesco Perpetual’s head of EM equities Dean Newman remarked: “I’m extremely pleased that Doug is joining our team and look forward to him applying the experience he has gained in Asia to the wider world of emerging markets.
“His arrival reinforces our strategy to further develop our emerging markets franchise to support this growing area of interest for our clients.”